Positional Astronomy


Astronomy research
Software instruments
   Stellar equation of states
   EOS with ionization
   EOS for supernovae
   Chemical potentials
   Stellar atmospheres
   Voigt Function
   Jeans escape
   Polytropic stars
   Cold white dwarfs
   Hotter white dwarfs
   Cold neutron stars
   Stellar opacities
   Neutrino energy loss rates
   Ephemeris routines
   Fermi-Dirac functions
   Galactic chemical evolution

   Nuclear reaction networks
   Nuclear statistical equilibrium
   Laminar deflagrations
   CJ detonations
   ZND detonations
   Fitting to conic sections
   Unusual linear algebra
   Derivatives on uneven grids
   Pentadiagonal solver
   Quadratics, Cubics, Quartics
   Supernova light curves
   Exact Riemann solutions
   1D PPM Hydrodynamics
   Verification problems
   Plane - Cube Intersection


   Zingale's software
   Brown's dStar
   GR1D code
   Iliadis' STARLIB database
   Herwig's NuGRID
   Meyer's NetNuc
Bicycle adventures

AAS Journals
2017 MESA Summer School
Teaching materials
Education and Public Outreach
2016 NSF SI2 PI Workshop

Contact: F.X.Timmes
my one page vitae,
full vitae,
research statement, and
teaching statement.
* This instrument computes the state vectors for the sun, the nine planets, the moon, the two martian satellites, four of the Galilean satellites, eight of saturns moons, six of uranian moons, thousands of comets, and half a million asteroids and other minor bodies. See JPL for the latest data files.

The values calculated compare favorably with JPL Horizons. A brief users guide is in this README, which is also included in the 117 MB public_ephem.tbz bzip2 tarball

Xephem by Elwood Downey is excellent, includes source code, and is a lot fun. Starry Night is not free, but a visually outstanding, particularily on openGL systems.

Both of these programs use the VSOP87 routines for the planetary state vectors; neither deploy the JPL ephemeris files or the USNO vector astrometry toolkit as used below.

* The public_ephem.tbz bzip2 tarball contains five data files:
unxp1550-2650.430 - JPL DE430 unix little-endian binary file for the sun, planets, and moon from +1550 to +2650. If you want other binaries or want to to roll your own binary files, visit JPL.
comet_elements.dat - JPL osculatory orbital elements for comets. Current as of 02Jan2016; get updated versions from DATSCOM.
numasteroids_elements.dat - JPL osculatory orbital elements for asteroids. current as of 02Jan2016; get updated versions from DATSCOM.
ephem.e15 - J2000 parameters for the Galilean satellites; from Jay Lieske.
redtass7.dat - time series arguments for eight of saturn's satellites; from BDL. Also check out the IERS site.

* The public_ephem.tbz bzip2 tarball contains twelve library files:
position_routine.f90 - main that returns the state vector.
ephem.dek - contains common block communications.
initialize_routine.f90 - initializations.
jpl_routines.f90 - customized version of the JPL routines that open, read, and interpolate the binary ephemeris files.
novas_routines.f90 - customized version of the USNO NOVAS routines.
fxt_routines.f90 - time and coordinate transforms, state vectors to orbital elements, exact two-body solutions, and more.
marsat_routines.f90 - planetocentric state vectors of the martian satellites, from Chapront-Touze 1990.
lieske_routines.f90 - planetocentric state vectors of the jovian satellites, from Lieske 1998.
satsat_routines.f90 - planetocentric state vectors of saturn's satellites, from Vienne & Duriez 1995.
gust86_routines.f90 - planetocentric state vectors of the uranian satellites, from Laskar & Jacobson 1987.
glue.f90 - date and time from machine, string parsers, string to real converteds and more.
trig_degrees.f90 - for compilers that don't support the circular functions in degrees.

* The public_ephem.tbz bzip2 tarball contains nine applications:
equinox.f90 - dates of equinoxes and solstices.
moon_phases.f90 - times of the lunar phases. flags conditions conducive for a potential lunar or solar eclipse.
perihelion.f90 - times of aphelions and perihelions. Here are a few periheleions and apheleions for Earth.
position.f90 - state vectors in equatorial, ecliptic, and alt-azi coordinate systems for geocentric, heliocentric or topographic centers.
retrograde.f90 - times of retrograde motion.
rise.f90 - rise, transit & set time of any object. It uses a bombproof, but slower, search method.
rise2.f90 - rise, transit & set time of any object. Using a fast iteration method, it can be fooled in unusual cases.
solar_eclipse.f90 - geographical track of a solar eclipse centerline, reporting total, partial, annular, or non-central phases.
within.f90 - dates when any two objects are within a given angular seperation.

Please cite the relevant references if you publish a piece of work that use these codes, pieces of these codes, or modified versions of them. Offer co-authorship as appropriate.